Various synthetic fluids, including synthetic hydrocarbons and silahydrocarbons, have been developed which are useful in the formulation of hydraulic fluids and lubricants which are stable at high temperatures. Tetraalkyl substituted silanes have been proposed for use in the formulation of hydraulic fluids and lubricants since they possess excellent viscosities over a wide temperature range and low pour points in addition to excellent thermal stability.
Various methods for the synthesis of tetraalkyl substituted silanes possessing the desired properties involving the addition of a Grignard reagent or alkyllithium compounds to alkyltrichlorosilanes have been reported in U.S. Pat. No. 4,367,343 to Tamborski et al; Rosenberg et al, J. Org. Chem., 1960, Vol. 25, pp. 243-248; pp. 142-145. The preparation of ethyl-substituted silanes from triethylaluminum and chloro- or alkylchlorosilanes is described in British Pat. No. 825,987 to Kali-Chemie Aktiengesellschaft. However, such lower alkylsubstituted silanes are unsuitable for use in the formulation of hydraulic fluids and lubricants which are stable at high temperatures.